Acoustic (e.g., ultrasound) imaging systems are being employed in an increasing number of contexts. An acoustic imaging system generally employs an acoustic probe for providing the acoustic beam to the area to be imaged and to receive the acoustic wave back from that area. An acoustic probe may employ an acoustic array to generate an acoustic beam which can be focused and steered to an area of interest. Acoustic arrays may be configured as a single row of acoustic elements, a one-dimensional (1D) array for imaging a two dimensional (2D) image plane, or as a two dimensional (2D) array for imaging a three dimensional region. Each of these acoustic elements includes an acoustic transducer element, and a corresponding acoustic element circuit. A 2D array comprises acoustic elements extending in both azimuth and elevation directions which can be operated fully independently to both focus and steer beams in any azimuth or elevation direction. These arrays can be configured in either flat or curved orientations.
Among the important parameters of an acoustic array that affect the performance of the acoustic probe and the acoustic imaging system are the pitch or spacing between adjacent acoustic elements and the size of the acoustic array. In particular, it is desired in some applications to provide a large acoustic array with a small pitch between adjacent acoustic elements. However, from a practical standpoint, it is difficult to produce a single semiconductor die to realize an acoustic array which is as large as might be desired. Furthermore, mounting a large semiconductor die on the curved surface of the housing of an acoustic probe can be problematic.
Accordingly, it would be desirable to provide an acoustic probe which includes a large acoustic array with small pitches between adjacent acoustic elements. It would further be desirable to provide a semiconductor die which can be employed in such an acoustic array. It would still further be desirable to provide a semiconductor wafer on which one or more such die can be fabricated.
In one aspect of the invention, a device comprises an acoustic probe having a plurality of acoustic array components separated and spaced apart from each other. Each of the acoustic array components comprises: an array of acoustic element circuits disposed contiguous to each other at a first pitch in at least a first direction; a plurality of pads each corresponding to one of the acoustic element circuits and formed within a circuitry area of the corresponding acoustic element circuit, the pads being arranged at a second pitch in at least the first direction; a plurality of interconnection bumps each corresponding to one of the pads and being disposed in electrical connection with the corresponding pad, wherein the interconnection bumps are disposed at a third pitch in at least the first direction; and a plurality of acoustic transducer elements on the interconnection bumps, wherein the acoustic transducer elements are disposed at a fourth pitch in at least a first direction, and wherein at least two of the first, second, third, and fourth pitches are different than each other.
In some embodiments, the third pitch is greater than the second pitch.
In some embodiments, the fourth pitch is greater than the third pitch.
In some embodiments, the second pitch is greater than the first pitch.
In some versions of these embodiments, the second pitch, third pitch, and fourth pitch are approximately the same as each other.
In some versions of these embodiments, the fourth pitch is substantially the same as the second pitch and the third pitch is greater than the fourth pitch.
In some versions of these embodiments, the second pitch is approximately the same as the first pitch.
In some versions of these embodiments, the third pitch is approximately the same as the first pitch, and the fourth pitch is greater than the first pitch.
In some versions of these embodiments, the third pitch is greater than the first pitch, and the fourth pitch is approximately the same as the third pitch.
In some embodiments, at least a first acoustic array component and a second acoustic array component among the plurality of acoustic array components are provided together on a common semiconductor substrate, wherein the pads of the first and second acoustic array components together form an array of pads, and wherein the pads of the first and second acoustic array components have a substantially uniform pitch throughout the array of pads.
In some versions of these embodiments, the acoustic transducer elements of the first and second acoustic array components together form an array of acoustic transducer elements, and wherein the acoustic transducer elements of the first and second acoustic array components have a substantially uniform pitch throughout the array of acoustic transducer elements.
In some embodiments, at least a first acoustic array component and a second acoustic array component among the plurality of acoustic array components are provided on different semiconductor substrates than each other, wherein the pads of the first and second acoustic array components together form an array of pads, and wherein the pads of the first and second acoustic array components have a substantially uniform pitch throughout the array of pads.
In some versions of these embodiments, the acoustic transducer elements of the first and second acoustic array components together form an array of acoustic transducer elements, and wherein the acoustic transducer elements of the first and second acoustic array components have a of acoustic transducer elements uniform pitch throughout the array of acoustic transducer elements.
In another aspect of the invention, a device comprises: a substrate including at least first and second circuit regions, wherein the first circuit region and the second circuit region are separated and spaced apart from each other by a scribing lane for scribing die from the substrate. Each of the circuit regions comprises: an array of acoustic element circuits disposed at a first pitch in at least a first direction; and a plurality of pads each corresponding to one of the acoustic element circuits and formed within a circuitry area of the corresponding acoustic element circuit, wherein the pads of the first and second circuit regions together form an array of pads having a substantially uniform pitch in at least the first direction throughout the array of pads, where the uniform pitch is a second pitch which is greater than the first pitch.
In some embodiments, the array of acoustic element circuits includes: a first acoustic element circuit at a first end of the array, the first acoustic element having a corresponding first pad; and a last acoustic element circuit at a second end of the array which is opposite the first end of the array, the last acoustic element having a corresponding last pad, wherein the first and last pads are disposed along opposite sides of the corresponding acoustic element circuits with respect to each other.
In some embodiments, the substrate includes at least third and fourth circuit regions, wherein the first, second, third, and fourth circuit regions form a two dimensional array and are separated and spaced apart from each other by one or more scribing lanes.
In some embodiments, the device further comprises a plurality of interconnection bumps each corresponding to one of the pads and being disposed in electrical connection with the corresponding pad.
In some versions of these embodiments, the device further comprises a plurality of acoustic transducer elements on the interconnection bumps, wherein the interconnection bumps.
In yet another aspect of the invention, a device comprises: an array of acoustic element circuits disposed on a substrate at a first pitch in at least a first direction; and a plurality of pads each corresponding to one of the acoustic element circuits and formed within a circuitry area of the corresponding acoustic element circuit, the pads being disposed at a second pitch in at least the first direction, wherein the second pitch is greater than the first pitch.
In some embodiments, the array of acoustic element circuits includes: a first acoustic element circuit at a first end of the array, the first acoustic element having a corresponding first pad; and a last acoustic element circuit at a second end of the array which is opposite the first end of the array, the last acoustic element having a corresponding last pad, wherein the first and last pads are disposed along opposite sides of the corresponding acoustic element circuits with respect to each other.
In some embodiments, the device further comprises: a plurality of interconnection bumps each corresponding to one of the pads and being disposed in electrical connection with the corresponding pad; and a plurality of acoustic transducer elements disposed on the interconnection bumps.